Aqueous humor pentraxin-3 levels in patients with diabetes mellitus

Purpose To evaluate aqueous humor (AH) pentraxin-3 (PTX3) levels in diabetic patients with and without diabetic retinopathy (DR). Methods In this prospective study, patients undergoing cataract surgery were enrolled. The study group was composed of 26 type-2 diabetic patients without DR (group 1), 32 diabetic patients with DR (group 2) and 29 age-matched subjects without any systemic disease (group 3). Fifteen proliferative DR (PDR) and 17 nonproliferative DR (NPDR) patients were enrolled in Group 2. HbA1c levels and duration of diabetes were noted. AH samples were obtained from anterior chamber at the beginning of cataract surgery and PTX3 levels were analyzed with Elisa kit. Results Baseline demographic characteristics were similar between groups. The mean duration of diabetes was 11.9 +/- 7.9 years in group 1 and 15.8 +/- 7.8 years in group 2 (P=0.11). The mean plasma HbA1c levels in group 1 was 9.1 +/- 2.6 and 8.2 +/- 2.4 in group 2 (P=0.36). PTX3 levels were 5.75 +/- 0.41 in group 1, 6.11 +/- 1.47 in group 2 and 4.93 +/- 0.84 ng/ml in group 3 (P=0.01). PTX3 levels in group 2 were higher than in group 1 and 3 (P=0.06 and P= 0.01, respectively). There was no correlation between HbA1c and PTX3 levels (P=0.06 r=0.57, P= 0.19 r=0.3, respectively). The mean PTX3 was 6.6 +/- 0.3 in PDR group and 5.6 +/- 0.5 ng/ml in NPDR group (P=0.04). Conclusions PTX3 is an important marker especially for vascular endothelial damage. Since diabetic vascular changes are dependent on endothelial cell damage, high levels of AH PTX3 of DR patients may indicate the importance of PTX3 protein in the pathogenesis of DR.